title: Contagion of deliberate self-harm among adolescent inpatients.
abstract: OBJECTIVE
  To explore the quantitative importance and clinical features of deliberate self-harm (DSH) contagion in a closed adolescent psychiatric unit.
  
  
  METHODS
  The authors investigated with statistical methods and a sociogram whether acts of DSH were clustered during a 12-month study period. Twelve subjects were involved in acts of DSH, and their mean length of hospitalization during the study period was about 90 days. Six adolescents with four or more contagion incidents were interviewed.
  
  
  RESULTS
  DSH incidents were clustered during the study period (p < .05). Most DSH incidents were skin cutting committed by depressed female subjects with borderline personality disorder. The majority of DSH contagion can be understood in terms of small-group rites for feelings of togetherness.
  
  
  CONCLUSIONS
  Even a majority of DSH events in closed adolescent units may be triggered by contagion, and DSH can spread to previously DSH-naive adolescents.
authors.affiliation: University of Turku, Finland.
authors.forename: T J
authors.initials: TJ
authors.lastname: Taiminen
authors.forename: K
authors.initials: K
authors.lastname: Kallio-Soukainen
authors.forename: H
authors.initials: H
authors.lastname: Nokso-Koivisto
authors.forename: A
authors.initials: A
authors.lastname: Kaljonen
authors.forename: H
authors.initials: H
authors.lastname: Helenius
mesh_terms: D000293:Adolescent; D000298:Adolescent, Hospitalized / Q000523:psychology; D016009:Chi-Square Distribution; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D000297:Psychology, Adolescent; D016728:Self-Injurious Behavior / Q000523:psychology*; D012932:Social Facilitation; D013029:Space-Time Clustering